Field of the Invention
The present invention relates to additives for scavenging hydrogen sulfide. The present invention particularly relates to additives for scavenging hydrogen sulfide based upon metals such as zinc.
Background of the Art
The presence of sulfur species in hydrocarbon fluids and aqueous streams is undesirable for various reasons. The subterranean reservoirs currently being developed have increased amounts of sulfur species within the produced hydrocarbon streams (oil and gas). Hydrogen sulfide and mercaptans are toxic gases that are heavier than air and are very corrosive to well and surface equipment.
During combustion, sulfur-rich hydrocarbon streams also produce heavy environmental pollution. When sulfur-rich streams contact metals, sulfur species lead to brittleness in carbon steels and to stress corrosion cracking in more highly alloyed materials. Moreover, hydrogen sulfide in various hydrocarbon or aqueous streams poses a safety hazard and a corrosion hazard.
Zinc octoate, among other zinc carboxylates, are effective hydrogen sulfide scavengers. However, for example, when zinc octoate is prepared at a ratio of zinc to octanoic acid of 1:2, it has a very high viscosity which makes it difficult to handle and use. It would thus be desirable in the art to prepare the zinc carboxylate hydrogen sulfide scavengers having comparatively low viscosity.